SPIEGEL: Professor Kaku, in your book you write about how we will be like gods in the future. Are you saying that our grandchildren will be gods? Isn’t that a bit immodest?

Kaku: Just think for a moment about our forefathers in the year 1900. They lived to be 49 years old on average and traveled with horse-drawn wagons. Long distance communication was yelling out the window. If these people could see us today with mobile phones at our ears, Facebook on our screens and traveling with planes they would consider us wizards.

SPIEGEL: It’s still a big step to go from wizards to gods.

Kaku: So what do gods do? Apollo has unlimited power from the sun, Zeus can turn himself into a swan or anything else and Venus has a perfect body. Gods can move objects with their mind, rearrange things, and have perfect bodies. Our grandchildren will be able to do just that.

SPIEGEL: Let’s do a little time traveling. Close your eyes and imagine waking up on a September morning in the year 2112. What do you see?

Kaku: More important than what I see, is what will be omnipresent. Intelligence will be everywhere in the future, just like electricity is everywhere today. We now just assume that there’s electricity in the walls, the floor, the ceiling. In the future we will assume that everything is intelligent, so intelligence will be everywhere and nowhere. As children, we will be taught how to manipulate things around us just by talking to them and thinking. Children will believe that everything is alive.

SPIEGEL: We’ll ask the question in a different way. What will we experience on this morning in 2112?

Kaku: When we wake up, the first thing we want to know is what’s going on in the world. So we put in our intelligent contact lenses and with a blink we are online. If you want information, movies, virtual reality, it is all in your contact lenses. Then we’ll drive to work.

SPIEGEL: Driving? How boring!

Kaku: Aw, you want to fly? Cars may even fly, but we will also be able to manipulate our cars just by thinking. So, if you want to get into your car, you simply think, and you call your car. The car drives itself, and boom, there you are.

SPIEGEL: So our grandchildren will fly to work. And what will change there?

Kaku: If you are a college student, you blink and you can see all the answers to the final examination by wearing your contact lenses. Artists will wave their hands in the air and create beautiful works of art. If you’re an architect, you will see what you are creating and just move towers, two apartment buildings around as you construct things.

SPIEGEL: Why do we have to even bother leaving the house if all of our needs, questions and desires are played out virtually on our grandiose contact lenses?

Kaku: Well, you will want to go outside because we are humans, and our personality hasn’t changed in 100,000 years. We’re social creatures. We like to size each other up, figure out who’s on first, who’s on second. But technology will be able to help with that. In 2100, for example, when you talk to people, you will see their biography listed right in front of you. If you are looking for a date, you sign up for a dating service. When you go outside and people walk by you, their faces light up if they’re available. If someone speaks to you in Chinese, your contact lens will translate from Chinese to English. We will still resist certain technologies, however, because they go against who we are.

SPIEGEL: What’s an example of that?

Kaku: The paperless office. The paperless office was a failure, because we like tangible things. If I give you a choice between tickets to see your favorite famous rock star or a video of a close-up of your favorite rock star, which would you choose?

SPIEGEL: The concert tickets naturally.

Kaku: That’s the caveman in us. The caveman in you says, “I want direct contact. I don’t want a picture.” The caveman in our body says once in a while, we have to go outside. We have to meet real people, talk to real people, and do real things.

SPIEGEL: Speaking of real things, we were fascinated by the toilet of the future described in your book.

Kaku: Yeah. You will still have to go to the bathroom because our biology hasn’t changed. But your toilet will have more computer power than a university hospital does today.

SPIEGEL: The toilet as a supercomputer?

Kaku: Your toilet will have a chip in it called a “DNA chip.” It will analyze enzymes, proteins and genes for cancer. In this way we will be able to fight cancer long before a tumor even has a chance to develop. We will be able to also detect other illnesses early and fight them. But we will still have the common cold. There are at least 300 different rhinoviruses and you need to have a vaccine for each one. No company is going to do that, because it is going to bankrupt a large corporation to make a vaccine for each of them.

SPIEGEL: What a defeat! Comfort us — did you not just refer to the perfect body of Venus?

Kaku: The nature of medicine will shift away from basically saving lives to perfection. We will be able to rearrange our own genome.

SPIEGEL: I assume that you mean to make ourselves prettier, stronger and generally better?

Kaku: Those ambitions will be there.

SPIEGEL: As we get a better handle on genetic technologies, won’t there be more of an urge to create designer babies?

Kaku: We need a debate about these issues. This is going to create societal problems. You have to have an educated public democratically debating how far to push our beautiful children and the human race.

SPIEGEL: Will we eventually be able to conquer death?

Kaku: Eternal life does not violate the laws of physics, surprisingly enough. After all, we only die because of one word: “error.” The longer we live, the more errors there are that are made by our bodies when they read our genes. That means cells get sluggish. The body doesn’t function as well as it could, which is why the skin ages. Then organs eventually fail, so that’s why we die.

SPIEGEL: What can we do about that?

Kaku: We know the genes that correct these things. So if we use genetic repair mechanisms, we might be able to repair cells so they don’t wear out, so they just keep on going. That is as real possibility. We will also be able to regenerate organs by growing new ones. That can already be done now.

SPIEGEL: Then we will get rid of death?

Kaku: In principle, yes.

SPIEGEL: Then how will we decide who gets to live and who must die? Who will be allowed to have children?

Kaku: I don’t think children or overpopulation are going to be a problem. When people live longer, they have fewer children. We see that in Japan, the US and in other countries where prosperity, education and urbanization are on the rise.

SPIEGEL: Okay, back to the toilet. What do I do when the toilet tells me that I have cancer cells?

Kaku: You talk to the wallpaper, and you say…

SPIEGEL: Excuse me, but you talk to the wallpaper?

Kaku: As I mentioned, everything will be intelligent, even the wallpaper. You talk to the wallpaper, and you say, “I want to see my doctor.” Boom! A doctor appears on the wall. It’s a RoboDoc, which looks like a doctor, talks like a doctor, but it’s actually an animated figure. It will tell you what is going on in your body and answers all medical questions with 99 percent accuracy, because it has the medical histories of everyone on the planet available.

SPIEGEL: Will we also have robot driving instructors and robot cooks?

Kaku: Yes, of course.

SPIEGEL: But aren’t robots still rather dumb, even after 50 years of research into artificial intelligence?

Kaku: That’s true. ASIMO, the best robot around today has the intelligence of a cockroach. However, that will change. In the coming decades, robots will be as smart as mice. Now, mice are very smart. They can scurry around, hide behind things, look for food. I can see that in 10, 20, 30 years, we will start to have mice robots, then rabbit robots, cat robots, dog robots, finally monkey robots maybe by the end of the century. They will do dirty, dull and dangerous jobs for us. That means they have to feel pain too.

SPIEGEL: Are you talking about machines with the ability to suffer?

Kaku: We will have to build robots with pain sensors in them, because we don’t want them to destroy themselves.

SPIEGEL: Then won’t we have to start talking about robot rights?

Kaku: Once we design robots that can feel pain, that’s a tricky point. At that point, people will say, “Well, they’re just like dogs and cats.”

SPIEGEL: When will machines become a threat, like HAL from the movie ‘2001?’

Kaku: At some point we can plant a chip in their electronic brains that shuts them down when they start to develop dangerous plans.

SPIEGEL: But won’t they be intelligent enough to take the chip out themselves?

Kaku: Sure, but that won’t happen until after 2100.

SPIEGEL: How comforting.

Kaku: Then we always have the option of making ourselves even smarter.

SPIEGEL: Are you referring to the old science fiction idea that our brains are immeasurably smart?

Kaku: Exactly, and spending the whole day calculating Einstein’s theory of relativity. I don’t seriously believe that. It goes back to the caveman in us. What do cavemen want? Cavemen want to have the respect of their peers. They want to look good to the opposite sex. They want prestige. If we’re stuck inside a computer calculating Einstein’s theory of relativity, who wants that?

SPIEGEL: The idea that one day we will all be Supermen or Superwomen sounds really tempting though.

Kaku: I think what’s going to happen is we will have avatars. They will have all these powers that we want — to be perfect, superhuman and good looking.

SPIEGEL: Great! Does that mean we can send our avatars to meetings that we don’t want to attend?

Kaku: You will send your avatars to the Moon or on virtual trips or whatever. But you also have the option of shutting it off and getting back to normal again. The average person will not necessarily want to be Superman, but they may want the option of being Superman for an afternoon. It’s nice to be Superman for an afternoon, but then to say, hey, “let’s go out and have a beer with friends.” Do you see what I’m saying?

SPIEGEL: Yes, of course. Atavism beats out the avatar. But just how strong are these caveman impulses? Could there one day be a movement against all of this new technology?

Kaku: Such movements always accompany technological changes. When the telephone first came out, it was very controversial. Throughout history, we only talked to friends, relatives, kids. That’s it, period. Then comes the telephone. There were many voices denouncing it, saying we had to go back to talking to our families, so on and so forth.

SPIEGEL: You claim in your book that we are the most important generation that has ever lived. Doesn’t every generation think that?

Kaku: Out of all the generations that have walked the surface of the Earth, we’re the only ones to witness the beginning of the process of becoming a planetary civilization. We decide whether humanity survives.

SPIEGEL: What do you mean by “planetary civilization?”

Kaku: We physicists rank civilizations by energy. A Type 1 planetary civilization uses all the energy that is available on the planet. In a hundred years, we’ll be Type 1. We’re on our way there. We will control the weather. We will control earthquakes and volcanoes eventually. Anything planetary, we will control. Type 2 is stellar. We will control stars, like Star Trek. Then Type 3 is the entire galaxy, where we’ll control the Milky Way galaxy.

SPIEGEL: Hold on a second. We aren’t even close to that now!

Kaku: No, we are in a transition. We still get our energy from dead plants, oil and coal. Carl Sagan did a more precise calculation. He figured out that we’re actually Type 0.7. So we’re on the threshold of being Type 1. We will have two planetary languages, English and Mandarin. Look at the Olympics. That’s planetary sports. Look at soccer, another planetary sport. The European Union is the beginning of a planetary economy, if it ever gets off the ground correctly.

SPIEGEL: We are having a few tiny problems with that last one.

Kaku: Well, nevertheless, when I look at the larger sweep of things, I see that we are already coming together. We’re entering the birth of a planetary fashion and we are already seeing the birth of planetary culture. Democratization of the world marches on.

SPIEGEL: What is one thing from the world you imagine that you would like to have today?

Kaku: Well, I wouldn’t mind having a few more decades to live and, for example, to see the first starship. Also, it’s a shame that I cannot live in the 11th dimension.

SPIEGEL: What do you mean by that?

Kaku: The energy of wormholes, black holes and of the Big Bang. You would have to be a Type 3 civilization before you can begin to manipulate that energy. That’s the province of my field of research, string theory.

SPIEGEL: I think that’s where we can no longer keep up. Professor Kaku, we thank you for this interview.